1. Field of the Disclosure
The invention is found in the field of multiple coaxial connectors according to the preamble of the independent patent claim.
2. Related Art
The prior art discloses multiple coaxial connectors which are suitable for simultaneously connecting a plurality of connectors to a coaxial cable guide. By way of example, the applicant discloses a 16-pin multiple coaxial connector with the product designation Mc16. This connector has a spacing of around 4 mm between the individual connectors and is suitable for frequencies of up to approximately 40 GHz. Likewise known is a single connector with the designation MMPX which is suitable for frequencies up to 65 GHz but has a comparatively high plugging force. Various products which are offered for transmitting signals at high frequencies are known from other manufacturers:                Gore UHD (coaxial connector, 6-9 GHz, 19 dB, <78 channels per square inch, stamped-and-bent interface, plastic injection-molded housing)        Tyco Nanonics multi coaxial connector (20 GHz, 2.54 mm center-center pitch, metal housing, similarly D-sub, max 1×9)        Tensolite HDRFi multi coaxial connector (40 GHz, 3.3 mm center-center pitch, metal housing, similarly D-sub or round, planar contact, approximately 40 channels per square inch in 11-D-sub)        Synergetix “spring contact fields” (up to 20 GHz, approximately 1.95 mm center-center pitch with the best arrangement for high-frequency contacts, open field, freely configurable, approximately 170 channels per square inch)        Hirose 2 mm coaxial backplane connector (3 GHz, 7.5 mm center-center pitch, fits in a 2 mm backplane grid)        backplane connector from Molex/Teradyne, ERNI, FCI (10-20 Gbps, few plugging cycles, density up to 300 channels per square inch)        
FCI discloses a connector system with the designation Airmax VS High Speed Connector System. The connectors are constructed from individual layers and do not have a shield. Therefore, they are suitable for transmitting high frequencies only to a limited extent.
EP1021852 was filed in the name of Tyco Electronics and relates to a coaxial RF connector for transmitting radio-frequency electromagnetic waves. The connector has a housing with at least one inner contact and with an outer contact which is arranged coaxially around the inner contact. EP1021852 is based on the object of developing an RF coaxial plug connector which can be produced in a simple and cost-effective manner with a sufficient outer conductor surface thickness. Furthermore, the RF coaxial plug connector which is to be developed should also ensure reliable electrical connection to an outer conductor of a mating coaxial plug, that is to say the outer conductor function. This object is intended to be achieved in that the housing is in the form of a plastic injection-molded part, and in that the housing has a wall section which is composed of plastic and is arranged coaxially around the inner contact, in which wall section at least the inner wall which faces the inner contact is provided with a sufficiently thick metallization layer.
Elektronik [Electronics] 7./8.4.82, page 146 already discloses providing a plastic housing in multipole plug connectors and providing this housing with a surface metallization for shielding purposes. However, these multipole plug connectors are not coaxial plug connectors in which there is always a contact pair comprising an inner contact/coaxial outer contact. Instead, these known plug connectors have a plurality of contact pins which are surrounded by a common housing border which is provided with surface metallization. Therefore, realizing an outer conductor function by means of metalizing a hollow-cylindrical inner wall of the housing does not play any role here.
EP0582960 was filed in the name of Siemens AG and relates to an RF coaxial plug connection with a plurality of coaxial plugs which are arranged at a specific pitch spacing on a substrate, for example a printed circuit board, and corresponding mating coaxial plug connectors which are arranged on a substrate. EP0582960 is based on the object of providing an RF coaxial plug connection which is suitable for a small pitch spacing of, for example, 5 mm, that is to say a mechanically and electrically adapted RF coaxial plug connection, using simplified connection technology. According to the description of EP0582960, the object is achieved by means of an RF coaxial plug connection having the following features: a) the coaxial plugs are secured on their substrate with press-in contacts, b) the mating plug connectors are integrated in a monobloc in a number which corresponds to the number of coaxial plugs, c) the monobloc is composed of conductive material and forms the outer conductor for all the mating coaxial plug connectors integrated in it, d) the inner conductors of the coaxial mating plug connectors and their connections to the substrate are in each case accommodated in an insulated manner in holes in the monobloc, e) the connections of the inner conductors of the coaxial mating plug connectors and the outer conductor connections of the monobloc are in the form of press-in contacts.
U.S. Pat. No. 4,571,014 from AT&T was filed in 1986 and discloses a plug connector with a large number of contacts and a modular, comparatively complicated construction. The connector is assembled from a large number of different parts and is intended to be suitable for use with printed circuit boards. The connector does not have a coaxial construction.
The plug connectors known from the prior art are not suitable for use in an array with a high packing density in the region of 100 channels per square inch, as are used, for example, in test arrangements for testing chips or microprocessors where a large number of connector points have to be simultaneously connected in a narrow space and high frequencies have to be transmitted. One reason for this is that, on account of the design, an arrangement with a corresponding packing density is not possible. It is likewise not possible to guarantee that all the connectors are reliably operatively connected to one another.
U.S. Pat. No. 5,190,472 was applied for by W. L. Gore & Associates, Inc. in 1992 and discloses a multiple coaxial connector which targets a high channel density. Individual coaxial connectors are half-inserted into comb-like, semicircular cutouts, which are arranged opposite one another on two sides, of a so-called grouping module from the side. Since the cutouts surround only half of each connector, the individual connectors are not held in the individual cutouts and fall out of them. The individual connectors are fixed and thus held only by a plurality of grouping modules being laterally layered one on the other. Without the layering, the grouping modules are not functional as such. The layered grouping modules which are fitted with the individual connectors are firmly pressed into an outer frame from behind, and thus joined to form a functional multiple coaxial connector. Although the described principle of a multiple coaxial connector theoretically allows multiple connectors with a comparatively high number of connectors, it has significant disadvantages. Firstly, assembly is extremely difficult. Secondly, the individual, very delicate connectors are held very firmly, and this has a negative effect when mounting connectors with a large number of channels on account of the tolerance chains which develop. A further disadvantage is the large number of very small and different components which are complicated to manufacture and therefore make the corresponding multiple coaxial connectors very expensive.